#include "Md5Util.h"


#define F(x, y, z)   ((z) ^ ((x) & ((y) ^ (z))))
#define G(x, y, z)   ((y) ^ ((z) & ((x) ^ (y))))
#define H(x, y, z)   ((x) ^ (y) ^ (z))
#define I(x, y, z)   ((y) ^ ((x) | ~(z)))
#define STEP(f, a, b, c, d, x, t, s) \
(a) += f((b), (c), (d)) + (x) + (t); \
(a) = (((a) << (s)) | (((a) & 0xffffffff) >> (32 - (s)))); \
(a) += (b);

#if defined(__i386__) || defined(__x86_64__) || defined(__vax__)
    #define SET(n) (*(MD5_u32 *)&ptr[(n) * 4])
    #define GET(n) SET(n)
#else
    #define SET(n) \
    (ctx->block[(n)] = \
    (MD5_u32)ptr[(n) * 4] | \
    ((MD5_u32)ptr[(n) * 4 + 1] << 8) | \
    ((MD5_u32)ptr[(n) * 4 + 2] << 16) | \
    ((MD5_u32)ptr[(n) * 4 + 3] << 24))
    #define GET(n) (ctx->block[(n)])
#endif

static const void *body(MD5_CTX *ctx, const void *data, unsigned long size){
    const unsigned char *ptr;
    MD5_u32 a, b, c, d;
    MD5_u32 saved_a, saved_b, saved_c, saved_d;
    
    ptr = (const unsigned char*)data;
    
    a = ctx->a;
    b = ctx->b;
    c = ctx->c;
    d = ctx->d;
    
    do {
        saved_a = a;
        saved_b = b;
        saved_c = c;
        saved_d = d;
        
        STEP(F, a, b, c, d, SET(0), 0xd76aa478, 7)
        STEP(F, d, a, b, c, SET(1), 0xe8c7b756, 12)
        STEP(F, c, d, a, b, SET(2), 0x242070db, 17)
        STEP(F, b, c, d, a, SET(3), 0xc1bdceee, 22)
        STEP(F, a, b, c, d, SET(4), 0xf57c0faf, 7)
        STEP(F, d, a, b, c, SET(5), 0x4787c62a, 12)
        STEP(F, c, d, a, b, SET(6), 0xa8304613, 17)
        STEP(F, b, c, d, a, SET(7), 0xfd469501, 22)
        STEP(F, a, b, c, d, SET(8), 0x698098d8, 7)
        STEP(F, d, a, b, c, SET(9), 0x8b44f7af, 12)
        STEP(F, c, d, a, b, SET(10), 0xffff5bb1, 17)
        STEP(F, b, c, d, a, SET(11), 0x895cd7be, 22)
        STEP(F, a, b, c, d, SET(12), 0x6b901122, 7)
        STEP(F, d, a, b, c, SET(13), 0xfd987193, 12)
        STEP(F, c, d, a, b, SET(14), 0xa679438e, 17)
        STEP(F, b, c, d, a, SET(15), 0x49b40821, 22)
        STEP(G, a, b, c, d, GET(1), 0xf61e2562, 5)
        STEP(G, d, a, b, c, GET(6), 0xc040b340, 9)
        STEP(G, c, d, a, b, GET(11), 0x265e5a51, 14)
        STEP(G, b, c, d, a, GET(0), 0xe9b6c7aa, 20)
        STEP(G, a, b, c, d, GET(5), 0xd62f105d, 5)
        STEP(G, d, a, b, c, GET(10), 0x02441453, 9)
        STEP(G, c, d, a, b, GET(15), 0xd8a1e681, 14)
        STEP(G, b, c, d, a, GET(4), 0xe7d3fbc8, 20)
        STEP(G, a, b, c, d, GET(9), 0x21e1cde6, 5)
        STEP(G, d, a, b, c, GET(14), 0xc33707d6, 9)
        STEP(G, c, d, a, b, GET(3), 0xf4d50d87, 14)
        STEP(G, b, c, d, a, GET(8), 0x455a14ed, 20)
        STEP(G, a, b, c, d, GET(13), 0xa9e3e905, 5)
        STEP(G, d, a, b, c, GET(2), 0xfcefa3f8, 9)
        STEP(G, c, d, a, b, GET(7), 0x676f02d9, 14)
        STEP(G, b, c, d, a, GET(12), 0x8d2a4c8a, 20)
        STEP(H, a, b, c, d, GET(5), 0xfffa3942, 4)
        STEP(H, d, a, b, c, GET(8), 0x8771f681, 11)
        STEP(H, c, d, a, b, GET(11), 0x6d9d6122, 16)
        STEP(H, b, c, d, a, GET(14), 0xfde5380c, 23)
        STEP(H, a, b, c, d, GET(1), 0xa4beea44, 4)
        STEP(H, d, a, b, c, GET(4), 0x4bdecfa9, 11)
        STEP(H, c, d, a, b, GET(7), 0xf6bb4b60, 16)
        STEP(H, b, c, d, a, GET(10), 0xbebfbc70, 23)
        STEP(H, a, b, c, d, GET(13), 0x289b7ec6, 4)
        STEP(H, d, a, b, c, GET(0), 0xeaa127fa, 11)
        STEP(H, c, d, a, b, GET(3), 0xd4ef3085, 16)
        STEP(H, b, c, d, a, GET(6), 0x04881d05, 23)
        STEP(H, a, b, c, d, GET(9), 0xd9d4d039, 4)
        STEP(H, d, a, b, c, GET(12), 0xe6db99e5, 11)
        STEP(H, c, d, a, b, GET(15), 0x1fa27cf8, 16)
        STEP(H, b, c, d, a, GET(2), 0xc4ac5665, 23)
        STEP(I, a, b, c, d, GET(0), 0xf4292244, 6)
        STEP(I, d, a, b, c, GET(7), 0x432aff97, 10)
        STEP(I, c, d, a, b, GET(14), 0xab9423a7, 15)
        STEP(I, b, c, d, a, GET(5), 0xfc93a039, 21)
        STEP(I, a, b, c, d, GET(12), 0x655b59c3, 6)
        STEP(I, d, a, b, c, GET(3), 0x8f0ccc92, 10)
        STEP(I, c, d, a, b, GET(10), 0xffeff47d, 15)
        STEP(I, b, c, d, a, GET(1), 0x85845dd1, 21)
        STEP(I, a, b, c, d, GET(8), 0x6fa87e4f, 6)
        STEP(I, d, a, b, c, GET(15), 0xfe2ce6e0, 10)
        STEP(I, c, d, a, b, GET(6), 0xa3014314, 15)
        STEP(I, b, c, d, a, GET(13), 0x4e0811a1, 21)
        STEP(I, a, b, c, d, GET(4), 0xf7537e82, 6)
        STEP(I, d, a, b, c, GET(11), 0xbd3af235, 10)
        STEP(I, c, d, a, b, GET(2), 0x2ad7d2bb, 15)
        STEP(I, b, c, d, a, GET(9), 0xeb86d391, 21)
        
        a += saved_a;
        b += saved_b;
        c += saved_c;
        d += saved_d;
        
        ptr += 64;
    } while (size -= 64);
    
    ctx->a = a;
    ctx->b = b;
    ctx->c = c;
    ctx->d = d;
    
    return ptr;
}

void MD5_Init(MD5_CTX *ctx){
    ctx->a = 0x67452301;
    ctx->b = 0xefcdab89;
    ctx->c = 0x98badcfe;
    ctx->d = 0x10325476;
    
    ctx->lo = 0;
    ctx->hi = 0;
}


void MD5_Update(MD5_CTX *ctx, const void *data, size_t size){
    MD5_u32 saved_lo;
    unsigned long used, free;
    
    saved_lo = ctx->lo;
    if ((ctx->lo = (saved_lo + size) & 0x1fffffff) < saved_lo)
        ctx->hi++;
    ctx->hi += size >> 29;
    used = saved_lo & 0x3f;
    
    if (used){
        free = 64 - used;
        if (size < free) {
            memcpy(&ctx->buffer[used], data, size);
            return;
        }
        
        memcpy(&ctx->buffer[used], data, free);
        data = (unsigned char *)data + free;
        size -= free;
        body(ctx, ctx->buffer, 64);
    }
    
    if (size >= 64) {
        data = body(ctx, data, size & ~(unsigned long)0x3f);
        size &= 0x3f;
    }
    
    memcpy(ctx->buffer, data, size);
}

void MD5_Final(unsigned char *result, MD5_CTX *ctx){
    unsigned long used, free;
    used = ctx->lo & 0x3f;
    ctx->buffer[used++] = 0x80;
    free = 64 - used;
    
    if (free < 8) {
        memset(&ctx->buffer[used], 0, free);
        body(ctx, ctx->buffer, 64);
        used = 0;
        free = 64;
    }
    
    memset(&ctx->buffer[used], 0, free - 8);
    
    ctx->lo <<= 3;
    ctx->buffer[56] = ctx->lo;
    ctx->buffer[57] = ctx->lo >> 8;
    ctx->buffer[58] = ctx->lo >> 16;
    ctx->buffer[59] = ctx->lo >> 24;
    ctx->buffer[60] = ctx->hi;
    ctx->buffer[61] = ctx->hi >> 8;
    ctx->buffer[62] = ctx->hi >> 16;
    ctx->buffer[63] = ctx->hi >> 24;
    body(ctx, ctx->buffer, 64);
    result[0] = ctx->a;
    result[1] = ctx->a >> 8;
    result[2] = ctx->a >> 16;
    result[3] = ctx->a >> 24;
    result[4] = ctx->b;
    result[5] = ctx->b >> 8;
    result[6] = ctx->b >> 16;
    result[7] = ctx->b >> 24;
    result[8] = ctx->c;
    result[9] = ctx->c >> 8;
    result[10] = ctx->c >> 16;
    result[11] = ctx->c >> 24;
    result[12] = ctx->d;
    result[13] = ctx->d >> 8;
    result[14] = ctx->d >> 16;
    result[15] = ctx->d >> 24;
    memset(ctx, 0, sizeof(*ctx));
}

/* Return Calculated raw result(always little-endian), the size is always 16 */
void md5bin(const void* dat, size_t len, unsigned char out[16]) {
    MD5_CTX c;
    MD5_Init(&c);
    MD5_Update(&c, dat, len);
    MD5_Final(out, &c);
}

static char hb2hex(unsigned char hb) {
    hb = hb & 0xF;
    return hb < 10 ? '0' + hb : hb - 10 + 'A';
}

void md5_len(const char* dat, size_t len,char* result) {
    int i;
    unsigned char out[16];
    md5bin(dat, len, out);
    for(i = 0; i < 16; ++ i) {
        result[i*2] = hb2hex(out[i] >> 4);
        result[i*2+1] = hb2hex(out[i]);
    }
    result[32] = '\0';
}

#if 1
void md5(const char* dat, unsigned int ulstrlen, char* result)
{
    md5_len(dat, (size_t)ulstrlen,result);
}

#else

void md5(const char* dat,char* result){
    md5_len(dat, (size_t)strlen(dat),result);
}
#endif 
